[ZOOM] Selection rectangle

[Rodrigue]

Hi ,

When I make a zoom, I would like to trace a selection rectangle on the canvas of the graph. Here is a picture :
http://cjoint.com/?cimhAKO5v7

TIA !
Cordially,
Rodrigue

[Narcís]

Hi Rodrigue,

You can do it using the Color Bands tool, you will find some examples of it in the features demo included with the TeeChart installation.

[Rodrigue]

Hi,

I've did it but it's very slow !
So I've made this code :

Code: Select all

void __fastcall TForm1::Chart1MouseDown(TObject *Sender,
      TMouseButton Button, TShiftState Shift, int X, int Y)
{
   if(Shift.Contains(ssLeft))
   {
      XStartPos = X;
      XStopPos  = X;
   }
}

//---------------------------------------------------------------------------
void __fastcall TForm1::Chart1MouseMove(TObject *Sender, TShiftState Shift,
      int X, int Y)
{
   if(Shift.Contains(ssLeft))
   {
      XStopPos = X;
      Chart1->Invalidate();
   }
}

//---------------------------------------------------------------------------
void __fastcall TForm1::Chart1BeforeDrawAxes(TObject *Sender)
{
      Chart1->Canvas->Rectangle(XStartPos, Chart1->LeftAxis->IStartPos, XStopPos, Chart1->LeftAxis->IEndPos);
}

//---------------------------------------------------------------------------

I've to hide/unhide the rectangle of selection but it works !

It is not as slow as by using the colorband but it is always slow.

I believe that the solution is more simple. My only question is :
Where to specify the color of the background rectangle selection who is draw when we zoom?

http://cjoint.com/?cirRvDHApp
http://cjoint.com/?cirR524NK7

Cordially,
Rodrigue

[Narcís]

Hi Rodrigue

Where to specify the color of the background rectangle selection who is draw when we zoom?

You can do it before drawing the rectangle setting Canvas Pen and Brush colors as:

Code: Select all

void __fastcall TForm1::Chart1BeforeDrawAxes(TObject *Sender)
{
        Chart1->Canvas->Pen->Color=clRed;
        Chart1->Canvas->Brush->Color=clBlue;
        Chart1->Canvas->Rectangle(XStartPos, Chart1->LeftAxis->IStartPos,
                                         XStopPos, Chart1->LeftAxis->IEndPos);
}

[Rodrigue]

Hi,

Thanks for your reply. I found easier :

Code: Select all

Chart1->Zoom->Brush->Color = clBlue;

(idem for color's Pen)

I've a problem of blink now !
I try to set :

Code: Select all

Chart1->DoubleBuffered = true;

But it's doesn't solve the problem ...

Very cordially,
Rodrigue

[Narcís]

Hi Rodrigue,

I've a problem of blink now !

I'm afraid there's no solution by now. I've included it on our wish list to be considered for future releases.

[Rodrigue]

Ok, no problem !